Zothecula writes: GE Aviation is developing a revolutionary new jet engine that aims to combine the best traits of turbojet and turbofan engines, delivering supersonic speed capability and fuel efficiency in one package. GE's ADVENT designs are based on new manufacturing technologies like 3-D printing of intricate cooling components and super-strong but lightweight ceramic matrix composites. These allow the manufacture of highly efficient jet engines operating at temperatures above the melting point of steel.